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Voice Stress Analysis (VSA) technology is said to record psychophysiological stress responses that are present in the human voice when a person suffers psychological stress in response to a stimulus (''e.g.'', a question), and the consequences of the person's answer may be dire.〔Ruiz, Selye, & Guell, 1990. "Voice analysis to predict the psychological or physical state of a speaker", ''Aviation, Space, and Environmental Medicine'', 1990. Ruiz ''et al.'' report that their “research suggests that psychological stress may be detected as acoustic modifications in the fundamental frequency of a speakers voice” and “that the fundamental frequency of the vocal signal is slowly modulated (8-14 Hz) during speech in an emotionally neutral situation. In situations demanding increased ‘mental or psychomotor’ activity, the 8-14 Hz modulation then decreases as the striated muscles surrounding the vocal cords contract in response to the arousal, thus limiting the natural trembling.”〕 ==Support and criticism== In a study published December 7, 2013, the International Journal of Electrical, Electronics and Computer Engineering (IJEECE) found that Voice Stress Analysis (VSA) technology can identify emotional stress better than polygraph.〔Patil, V. P., Nayak, K. K., & Saxena, M. ("Voice Stress Detection" ), 2, 148-154. Journal of Electrical, Electronics and Computer Engineering'', IJEECE (online) ISSN 1748-8893.〕 An 18 year study conducted by Dr. James L. Chapman, Professor Emeritus, Former Director of Forensic Crime Laboratory, State University of New York at Corning, evaluated the use of the Voice Stress Analysis technology for the detection of stress associated with possible deception. Using a combinatorial approach of VSA and a standardized questioning process, Dr. Chapman was able to show that VSA detected stress associated with criminal activities in 95% of the confession obtained cases studied. Dr. Chapman found no cases wherein a confession was obtained in the absence of stress. In particular, the most considerable stress levels were detected during the investigation of murder, grand larceny and sexual crimes. Dr. Chapman identified that when VSA is utilized as an investigative decision support tool in accordance with required operating procedures, and standard VSA interviewing techniques are employed, elicited confessions from criminal suspects can strongly be predicted based upon results of their VSA examinations. Further, VSA can be used by trained professionals to support the acquisition of court admissible criminal confessions at a rate superior to other legal interrogation methods currently employed by the criminal justice system.〔Chapman, J. (2012). ("Field Evaluation of Effectiveness of VSA (Voice Stress Analysis) Technology in a US Criminal Justice Setting" ). Scientific Journal Criminalistics and Court Expertise, Number 57 (2012 Annual Issue), 238-250.〕 Proceedings of the 2005 Hawaii International Conference on System Sciences, identified that VSA technology can identify stress better than chance with performance approaching that of current polygraph systems.〔Sprague, R. H. (2005). ("Evaluation of Voice Stress Analysis Technology" ). HICSS 2005 38th Hawaii International International Conference on Systems Science (03-06 January 2005/Big Island, HI). Los Alamitos: IEEE Computer Society Press.〕 In a three year study conducted by the U.S. Air Force Research Laboratory in Rome New York, on voice stress analysis, it was determined that the voice stress units tested were able to recognize stress in the spoken voice. Additionally, these units performed equally whether the voice was a live test or a recorded one. The study also provided the caveat that caution should be taken when using voice stress analysis in that it should only be used as an investigative tool and not relied on for a case conclusion.〔Haddad, D., Walter, S., Ratley, R., & Smith, M. (2001). "Investigation and Evaluation of Voice Stress Analysis Technologies." Rome Laboratory Report (AFRL-IF-RS-TM-2001-7), 18-19.〕 Federally funded research via the American Polygraph Association in the United States showed "little validity" in the technique.〔Refer NAS 2003 in reference to all APA related research projects.〕 The U.S. Supreme Court identified in a land-mark ruling involving the use of polygraph, that it was "no more accurate than coin flip."〔United States v. Scheffer (96-1133) Supreme Court ruling, 31 March 1998.()〕 There is tension between the voice stress analysis community and the polygraph community, due to the fact that the polygraph is heavily regulated and has been subject to numerous detailed, contentious scientific studies, while voice stress analysis is largely unregulated. However, there are studies which show VSA results to be even slightly better than chance.〔Haddad, Walters Study 2002, doc 193832〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Voice stress analysis」の詳細全文を読む スポンサード リンク
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